Sheet-metal elbow.



No. 69l,l50. Patented Ian. M, I902.

0.- H. LAWRENCE.

SHEET METAL ausow.

[Application filed June 25, 1901.)

(No Model.)

THE NORRIS PETERS c0 pncnuumm WASNINGTON, n. c.

UNITE- dramas PATENT prion.

ORVILLE H. LAWRENCE, OF WVAVERLY, NEW YORK.

SHEET-METAL ELBOW.

SPECIFICATION forming part of Letters Patent No. 691,150, dated January 14, 1902.

Application filed June 25, 1901. Serial No. 65.971- Kllo model.)

To all whom it may concern:

Be it known that I, ORVILLE H. LAWRENCE,

a citizen of the United States, residing at Waverly, in the county of Tioga and State of New York, have invented certain new and useful Improvements in Sheet-Metal Elbows; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to pipe-elbows made of sheet metal, particularly elbows for rainwater pipes or pipes for conducting any liquid substance where a pipe with a smooth inside surface is required, the object being to provide an improved elbow for pipes of the described class.

Vith this object in view the invention consists in an elbow or bend for a pipe having a plurality of flat folds or crimps extending entirely around the pipe and locked together on the inner or throat side of the elbow at the longitudinally-meeting edges of the metal of which the elbow is made.

In the accompanying drawings, which illus' trate an elbow carrying out my invention, Figure 1 is a central longitudinal section through an elbow complete. Fig. 2 is a detail sectional view, on an enlarged scale, through the joint formed at the meeting edges of the metal of which the elbow is made. Fig. 3 is a detail View of a transverse section through a portion of the joint, showing the effect of punching.

Like letters of reference mark the same parts wherever they occur in the drawings.

Referring to the drawings by letters, A and 13 indicate the ends of the elbow when finished, which are at an angle to each otherusually a right angle, though not necessarily so.

In the manufacture of the elbow a flat blank of metal is used, in which a number of flat folds C are made of such form that when the blank is bent into shape for an elbow that portion of each of said folds which is on the inside or throat of the elbow, as at D, is of a much greater width than that portion on the outer side of the elbow, as at E; but it will be observed that both the outer and the inner folds, while of different widths, as before stated, lie flat against the material of the body of the elbow. The material between each of the folds is bent inward, as at F, connecting the outer layer of one fold with the inner layer of the next adjacent fold in such a manner that the general contour of the inner surface of the elbow is smooth, but lies in the same plane or curve, the surplus metal be ing contained entirely in the two outer layers of the folds upon the outer surface of the elbow, leaving its inner surface without appreciable obstruction to the passage of any liquid or substance through it. The folds on the inner or throat side of the elbow occupy so much of the surface that in effect they triple the thickness of the material which they join and form a brace or stifiener for the structure. After the folds have been formed, as described, the edges of the material, including the folds, are bent over, one inward, as at G, and the other outward, as at H, these edges being hooked one within the other, as particularly shown in Fig. 2, in which position they will be held by the natural tendency of the material to spread apart or flatten if released; but as a further security against displacement of the edges when overlapping on the angular part are indented or punched into each other, as shown at I in Fig. 3, thus firmly securing the overlapping joint.

It will be observed that in my construction as described no corrugations are shown to interfere with the passage of material through the elbow and that no solder is necessary, thus insuring material a free passage through the elbow and economizing in time and man ufacture of material and in the cost of the finished article, while making it much 'more durable.

The diameter of an elbow constructed in accordance with my invention is not reduced by taking up the surplus metal in fiat folds or crimping, as described; but the difierence exists in having a truss formed of a double thickness of metal around the whole circumference of the elbow.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A pipe-elbow formed of a straight blank in which are fiat folds or crimps of metal extending entirely around the circumference of the elbow when bent into form, substantially as described.

2. A pipe-elbow provided With flat folds or crimps extending entirely around its circumference, increasing in Width from the outer convex side to the inner or throat side of the elbow, the surplus metal being entirely upon the outside of the elbow, the interior being smooth, substantially as described.

3. A pipe or elbow having crimps or folds extending around its entire circumference, and provided with a hooked joint at the meeting edges of the blank, substantially as described.

4. A pipe-elbow provided with flat folds or crimps extending entirely around the circumference and formed Wholly on the outside surface, leaving the interior smooth and practically uninterrupted and of its original diameter, the edges being joined by a hooked joint, substantially as described.

5. A pipe-elbow having fiat folds or orimps of greater Width on the inner or throat side, and gradually decreasing to the outer side and extending entirely around the circumference of said elbow, all the surplus metal being folded on the outside, leaving the interior substantially uninterrupted and of its original diameter, the meeting edges, including the edges of the folds, being bent over in opposite directions to form a hook-joint, substantially as described.

In testimony whereof I hereunto affix my signature in presence of two Witnesses.

' ORVILLE H. LAWRENCE.

Witnesses:

SEWARD BALDWIN, FRED. L. MAXWELL. 

